I've attached a picture of a motor I'm thinking of buying but the guy isn't sure what year it is and the water pump assembly looks a bit different from the ones I've seen, so I'm hoping someone can help me out.

 

Do you have any bigger pictures? There aren't any mounts on the front cover, and the water pump housing looks very early.

 

Get a few more pictures, can't tell much from that!

 

Not sure but i see a dizzy and a carb

 

I bought the motor and I think it's a mixture of different years. The front cover is from and S5, but I'm pretty sure the rest isn't. It has the motor mounts underneath so it would have to be an 86 or newer, but it doesn't have the little holes above the trailing spark plugs like the S5 do (I thought that was true of all S5's). The exhaust ports have had the diffusers removed and have been enlarged on the outside to 2 1/2 inches across, the ones on my 86 and 90 were about 2 inches across. I took some pictures where you can see the exhaust ports and am hoping someone can help me know if the exhaust has been ported or not.

 

I went out and took more pictures in hopes of getting some confirmation on what I think. I am pretty sure it is a S4 motor with an S5 front cover, water pump housing from an older 13b, and from what I can tell the exhaust sleeves have been removed but no exhaust porting has been done (I've pulled up some other threads on here that had some pictures of porting and mine look like the before pictures more than the after). I am trying to figure out what the hose on the bottom left of the front of the motor is/was for since there was nothing there on either of the others I've had so if anyone has any clue on that let me know.

 

Frankenstein motor

 

Looks like a mixture of S4/S5 parts.

 

Hopefully it'll run good at least. I'm just waiting for a counterweight so I can bolt my flywheel on and find out, it should be here tomorrow and I'll put it in after work.

 

Everything's bolted up and I've managed to get it running a time or two but the front pulley was off an earlier model that would bolt on in any position and it was off from where it should've been. I now adjusted it and need to put my new starter in and make sure it runs right.